2024 – Lou Patron

My name is Lou Patron and I am a second-year PhD student at the GENALG laboratory at Ifremer in Nantes. My research focuses on the biotic interactions between the ichthyotoxic microalga Prymnesium parvum and its associated bacteria. This microalga is known for its massive blooms and its ability to produce toxins, causing major disturbances in aquatic ecosystems, particularly through the mass mortality of fish and other marine organisms.

My thesis project aims to explore the influence of these interactions on algae growth and toxin production. An essential part of my project involves identifying the bacteria present in the P. parvum microbiome. To do this, I use experimental approaches, including culture and genomic sequencing, as well as environmental analyses based on public databases, such as Tara Oceans. Certain bacteria are then selected and studied in co-culture with P. parvum in controlled environments to understand their potential role in modulating the physiological responses of P. parvum. In-depth genomic analyses are performed on these co-cultures to study the molecular mechanisms that govern the interactions between P. parvum and bacteria. For example, in a medium limited in vitamin B12, the objective is to determine whether, despite the stress of the limitation, P. parvum can grow thanks to the sharing of the vitamin by the bacteria. Ultimately, my work provides a better understanding of the mechanisms involved in these complex biotic interactions.

I would like to thank the French Phycological Society (SPF) for awarding me a grant that enabled me to present my findings at the M₂C₂ Marine Microbial Chemical Communication conference in March 2025.